]> git.ipfire.org Git - thirdparty/systemd.git/blame - src/shared/json.h
Merge pull request #15626 from poettering/more-specifiers
[thirdparty/systemd.git] / src / shared / json.h
CommitLineData
cd0b6c53 1/* SPDX-License-Identifier: LGPL-2.1+ */
cd0b6c53
LP
2#pragma once
3
f325aaf3 4#include <fcntl.h>
cd0b6c53
LP
5#include <stdbool.h>
6#include <stddef.h>
7#include <stdint.h>
ca78ad1d 8#include <stdio.h>
cd0b6c53
LP
9
10#include "macro.h"
11#include "string-util.h"
ca78ad1d 12#include "log.h"
cd0b6c53
LP
13
14/*
15 In case you wonder why we have our own JSON implementation, here are a couple of reasons why this implementation has
5238e957 16 benefits over various other implementations:
cd0b6c53
LP
17
18 - We need support for 64bit signed and unsigned integers, i.e. the full 64,5bit range of -9223372036854775808…18446744073709551615
19 - All our variants are immutable after creation
20 - Special values such as true, false, zero, null, empty strings, empty array, empty objects require zero dynamic memory
21 - Progressive parsing
22 - Our integer/real type implicitly converts, but only if that's safe and loss-lessly possible
23 - There's a "builder" for putting together objects easily in varargs function calls
24 - There's a "dispatcher" for mapping objects to C data structures
25 - Every variant optionally carries parsing location information, which simplifies debugging and parse log error generation
26 - Formatter has color, line, column support
27
28 Limitations:
29 - Doesn't allow embedded NUL in strings
30 - Can't store integers outside of the -9223372036854775808…18446744073709551615 range (it will use 'long double' for
31 values outside this range, which is lossy)
32 - Can't store negative zero (will be treated identical to positive zero, and not retained across serialization)
33 - Can't store non-integer numbers that can't be stored in "long double" losslessly
34 - Allows creation and parsing of objects with duplicate keys. The "dispatcher" will refuse them however. This means
35 we can parse and pass around such objects, but will carefully refuse them when we convert them into our own data.
36
37 (These limitations should be pretty much in line with those of other JSON implementations, in fact might be less
38 limiting in most cases even.)
39*/
40
41typedef struct JsonVariant JsonVariant;
42
43typedef enum JsonVariantType {
44 JSON_VARIANT_STRING,
45 JSON_VARIANT_INTEGER,
46 JSON_VARIANT_UNSIGNED,
47 JSON_VARIANT_REAL,
48 JSON_VARIANT_NUMBER, /* This a pseudo-type: we can never create variants of this type, but we use it as wildcard check for the above three types */
49 JSON_VARIANT_BOOLEAN,
50 JSON_VARIANT_ARRAY,
51 JSON_VARIANT_OBJECT,
52 JSON_VARIANT_NULL,
53 _JSON_VARIANT_TYPE_MAX,
54 _JSON_VARIANT_TYPE_INVALID = -1
55} JsonVariantType;
56
57int json_variant_new_stringn(JsonVariant **ret, const char *s, size_t n);
cc164891 58int json_variant_new_base64(JsonVariant **ret, const void *p, size_t n);
cd0b6c53
LP
59int json_variant_new_integer(JsonVariant **ret, intmax_t i);
60int json_variant_new_unsigned(JsonVariant **ret, uintmax_t u);
61int json_variant_new_real(JsonVariant **ret, long double d);
62int json_variant_new_boolean(JsonVariant **ret, bool b);
63int json_variant_new_array(JsonVariant **ret, JsonVariant **array, size_t n);
64int json_variant_new_array_bytes(JsonVariant **ret, const void *p, size_t n);
65int json_variant_new_array_strv(JsonVariant **ret, char **l);
66int json_variant_new_object(JsonVariant **ret, JsonVariant **array, size_t n);
67int json_variant_new_null(JsonVariant **ret);
68
69static inline int json_variant_new_string(JsonVariant **ret, const char *s) {
cbb3092c 70 return json_variant_new_stringn(ret, s, (size_t) -1);
cd0b6c53
LP
71}
72
73JsonVariant *json_variant_ref(JsonVariant *v);
74JsonVariant *json_variant_unref(JsonVariant *v);
75void json_variant_unref_many(JsonVariant **array, size_t n);
76
77DEFINE_TRIVIAL_CLEANUP_FUNC(JsonVariant *, json_variant_unref);
78
79const char *json_variant_string(JsonVariant *v);
80intmax_t json_variant_integer(JsonVariant *v);
81uintmax_t json_variant_unsigned(JsonVariant *v);
82long double json_variant_real(JsonVariant *v);
83bool json_variant_boolean(JsonVariant *v);
84
85JsonVariantType json_variant_type(JsonVariant *v);
86bool json_variant_has_type(JsonVariant *v, JsonVariantType type);
87
88static inline bool json_variant_is_string(JsonVariant *v) {
89 return json_variant_has_type(v, JSON_VARIANT_STRING);
90}
91
92static inline bool json_variant_is_integer(JsonVariant *v) {
93 return json_variant_has_type(v, JSON_VARIANT_INTEGER);
94}
95
96static inline bool json_variant_is_unsigned(JsonVariant *v) {
97 return json_variant_has_type(v, JSON_VARIANT_UNSIGNED);
98}
99
100static inline bool json_variant_is_real(JsonVariant *v) {
101 return json_variant_has_type(v, JSON_VARIANT_REAL);
102}
103
104static inline bool json_variant_is_number(JsonVariant *v) {
105 return json_variant_has_type(v, JSON_VARIANT_NUMBER);
106}
107
108static inline bool json_variant_is_boolean(JsonVariant *v) {
109 return json_variant_has_type(v, JSON_VARIANT_BOOLEAN);
110}
111
112static inline bool json_variant_is_array(JsonVariant *v) {
113 return json_variant_has_type(v, JSON_VARIANT_ARRAY);
114}
115
116static inline bool json_variant_is_object(JsonVariant *v) {
117 return json_variant_has_type(v, JSON_VARIANT_OBJECT);
118}
119
120static inline bool json_variant_is_null(JsonVariant *v) {
121 return json_variant_has_type(v, JSON_VARIANT_NULL);
122}
123
124bool json_variant_is_negative(JsonVariant *v);
e787b211
LP
125bool json_variant_is_blank_object(JsonVariant *v);
126bool json_variant_is_blank_array(JsonVariant *v);
b7fc90a2
LP
127bool json_variant_is_normalized(JsonVariant *v);
128bool json_variant_is_sorted(JsonVariant *v);
cd0b6c53
LP
129
130size_t json_variant_elements(JsonVariant *v);
131JsonVariant *json_variant_by_index(JsonVariant *v, size_t index);
132JsonVariant *json_variant_by_key(JsonVariant *v, const char *key);
133JsonVariant *json_variant_by_key_full(JsonVariant *v, const char *key, JsonVariant **ret_key);
134
135bool json_variant_equal(JsonVariant *a, JsonVariant *b);
136
83bc6cb7
LP
137void json_variant_sensitive(JsonVariant *v);
138
cd0b6c53
LP
139struct json_variant_foreach_state {
140 JsonVariant *variant;
141 size_t idx;
142};
143
144#define JSON_VARIANT_ARRAY_FOREACH(i, v) \
145 for (struct json_variant_foreach_state _state = { (v), 0 }; \
1b266e3c
LP
146 json_variant_is_array(_state.variant) && \
147 _state.idx < json_variant_elements(_state.variant) && \
cd0b6c53
LP
148 ({ i = json_variant_by_index(_state.variant, _state.idx); \
149 true; }); \
150 _state.idx++)
151
152#define JSON_VARIANT_OBJECT_FOREACH(k, e, v) \
153 for (struct json_variant_foreach_state _state = { (v), 0 }; \
1b266e3c
LP
154 json_variant_is_object(_state.variant) && \
155 _state.idx < json_variant_elements(_state.variant) && \
33d60b8d 156 ({ k = json_variant_string(json_variant_by_index(_state.variant, _state.idx)); \
cd0b6c53
LP
157 e = json_variant_by_index(_state.variant, _state.idx + 1); \
158 true; }); \
159 _state.idx += 2)
160
161int json_variant_get_source(JsonVariant *v, const char **ret_source, unsigned *ret_line, unsigned *ret_column);
162
897f099b 163typedef enum JsonFormatFlags {
2d814304
LP
164 JSON_FORMAT_NEWLINE = 1 << 0, /* suffix with newline */
165 JSON_FORMAT_PRETTY = 1 << 1, /* add internal whitespace to appeal to human readers */
166 JSON_FORMAT_PRETTY_AUTO = 1 << 2, /* same, but only if connected to a tty (and JSON_FORMAT_NEWLINE otherwise) */
167 JSON_FORMAT_COLOR = 1 << 3, /* insert ANSI color sequences */
168 JSON_FORMAT_COLOR_AUTO = 1 << 4, /* insert ANSI color sequences if colors_enabled() says so */
169 JSON_FORMAT_SOURCE = 1 << 5, /* prefix with source filename/line/column */
170 JSON_FORMAT_SSE = 1 << 6, /* prefix/suffix with W3C server-sent events */
171 JSON_FORMAT_SEQ = 1 << 7, /* prefix/suffix with RFC 7464 application/json-seq */
172 JSON_FORMAT_FLUSH = 1 << 8, /* call fflush() after dumping JSON */
897f099b 173} JsonFormatFlags;
cd0b6c53 174
897f099b
LP
175int json_variant_format(JsonVariant *v, JsonFormatFlags flags, char **ret);
176void json_variant_dump(JsonVariant *v, JsonFormatFlags flags, FILE *f, const char *prefix);
cd0b6c53 177
f2ff34ff
LP
178int json_variant_filter(JsonVariant **v, char **to_remove);
179
78a41236 180int json_variant_set_field(JsonVariant **v, const char *field, JsonVariant *value);
15f1fb3e 181int json_variant_set_field_string(JsonVariant **v, const char *field, const char *value);
a832b08e 182int json_variant_set_field_integer(JsonVariant **v, const char *field, intmax_t value);
15f1fb3e 183int json_variant_set_field_unsigned(JsonVariant **v, const char *field, uintmax_t value);
a832b08e 184int json_variant_set_field_boolean(JsonVariant **v, const char *field, bool b);
78a41236 185
21e21511
LP
186int json_variant_append_array(JsonVariant **v, JsonVariant *element);
187
ca409a59
LP
188int json_variant_merge(JsonVariant **v, JsonVariant *m);
189
22f14d6b
LP
190int json_variant_strv(JsonVariant *v, char ***ret);
191
b7fc90a2
LP
192int json_variant_sort(JsonVariant **v);
193int json_variant_normalize(JsonVariant **v);
194
d642f640
LP
195typedef enum JsonParseFlags {
196 JSON_PARSE_SENSITIVE = 1 << 0, /* mark variant as "sensitive", i.e. something containing secret key material or such */
197} JsonParseFlags;
f325aaf3 198
d642f640
LP
199int json_parse(const char *string, JsonParseFlags flags, JsonVariant **ret, unsigned *ret_line, unsigned *ret_column);
200int json_parse_continue(const char **p, JsonParseFlags flags, JsonVariant **ret, unsigned *ret_line, unsigned *ret_column);
201int json_parse_file_at(FILE *f, int dir_fd, const char *path, JsonParseFlags flags, JsonVariant **ret, unsigned *ret_line, unsigned *ret_column);
202
203static inline int json_parse_file(FILE *f, const char *path, JsonParseFlags flags, JsonVariant **ret, unsigned *ret_line, unsigned *ret_column) {
204 return json_parse_file_at(f, AT_FDCWD, path, flags, ret, ret_line, ret_column);
f325aaf3 205}
cd0b6c53
LP
206
207enum {
208 _JSON_BUILD_STRING,
209 _JSON_BUILD_INTEGER,
210 _JSON_BUILD_UNSIGNED,
211 _JSON_BUILD_REAL,
212 _JSON_BUILD_BOOLEAN,
213 _JSON_BUILD_ARRAY_BEGIN,
214 _JSON_BUILD_ARRAY_END,
215 _JSON_BUILD_OBJECT_BEGIN,
216 _JSON_BUILD_OBJECT_END,
217 _JSON_BUILD_PAIR,
319a4f27 218 _JSON_BUILD_PAIR_CONDITION,
cd0b6c53
LP
219 _JSON_BUILD_NULL,
220 _JSON_BUILD_VARIANT,
e4defdc4 221 _JSON_BUILD_VARIANT_ARRAY,
cd0b6c53
LP
222 _JSON_BUILD_LITERAL,
223 _JSON_BUILD_STRV,
886b0c93 224 _JSON_BUILD_BASE64,
cd0b6c53
LP
225 _JSON_BUILD_MAX,
226};
227
228#define JSON_BUILD_STRING(s) _JSON_BUILD_STRING, ({ const char *_x = s; _x; })
229#define JSON_BUILD_INTEGER(i) _JSON_BUILD_INTEGER, ({ intmax_t _x = i; _x; })
230#define JSON_BUILD_UNSIGNED(u) _JSON_BUILD_UNSIGNED, ({ uintmax_t _x = u; _x; })
231#define JSON_BUILD_REAL(d) _JSON_BUILD_REAL, ({ long double _x = d; _x; })
232#define JSON_BUILD_BOOLEAN(b) _JSON_BUILD_BOOLEAN, ({ bool _x = b; _x; })
233#define JSON_BUILD_ARRAY(...) _JSON_BUILD_ARRAY_BEGIN, __VA_ARGS__, _JSON_BUILD_ARRAY_END
aafa52ab 234#define JSON_BUILD_EMPTY_ARRAY _JSON_BUILD_ARRAY_BEGIN, _JSON_BUILD_ARRAY_END
cd0b6c53 235#define JSON_BUILD_OBJECT(...) _JSON_BUILD_OBJECT_BEGIN, __VA_ARGS__, _JSON_BUILD_OBJECT_END
aafa52ab 236#define JSON_BUILD_EMPTY_OBJECT _JSON_BUILD_OBJECT_BEGIN, _JSON_BUILD_OBJECT_END
cd0b6c53 237#define JSON_BUILD_PAIR(n, ...) _JSON_BUILD_PAIR, ({ const char *_x = n; _x; }), __VA_ARGS__
319a4f27 238#define JSON_BUILD_PAIR_CONDITION(c, n, ...) _JSON_BUILD_PAIR_CONDITION, ({ bool _x = c; _x; }), ({ const char *_x = n; _x; }), __VA_ARGS__
cd0b6c53
LP
239#define JSON_BUILD_NULL _JSON_BUILD_NULL
240#define JSON_BUILD_VARIANT(v) _JSON_BUILD_VARIANT, ({ JsonVariant *_x = v; _x; })
e4defdc4 241#define JSON_BUILD_VARIANT_ARRAY(v, n) _JSON_BUILD_VARIANT_ARRAY, ({ JsonVariant **_x = v; _x; }), ({ size_t _y = n; _y; })
cd0b6c53
LP
242#define JSON_BUILD_LITERAL(l) _JSON_BUILD_LITERAL, ({ const char *_x = l; _x; })
243#define JSON_BUILD_STRV(l) _JSON_BUILD_STRV, ({ char **_x = l; _x; })
886b0c93 244#define JSON_BUILD_BASE64(p, n) _JSON_BUILD_BASE64, ({ const void *_x = p; _x; }), ({ size_t _y = n; _y; })
cd0b6c53
LP
245
246int json_build(JsonVariant **ret, ...);
247int json_buildv(JsonVariant **ret, va_list ap);
248
249/* A bitmask of flags used by the dispatch logic. Note that this is a combined bit mask, that is generated from the bit
250 * mask originally passed into json_dispatch(), the individual bitmask associated with the static JsonDispatch callout
251 * entry, as well the bitmask specified for json_log() calls */
252typedef enum JsonDispatchFlags {
253 /* The following three may be set in JsonDispatch's .flags field or the json_dispatch() flags parameter */
254 JSON_PERMISSIVE = 1 << 0, /* Shall parsing errors be considered fatal for this property? */
5238e957 255 JSON_MANDATORY = 1 << 1, /* Should existence of this property be mandatory? */
cd0b6c53 256 JSON_LOG = 1 << 2, /* Should the parser log about errors? */
ba23dbf1 257 JSON_SAFE = 1 << 3, /* Don't accept "unsafe" strings in json_dispatch_string() + json_dispatch_string() */
7a8867ab 258 JSON_RELAX = 1 << 4, /* Use relaxed user name checking in json_dispatch_user_group_name */
cd0b6c53
LP
259
260 /* The following two may be passed into log_json() in addition to the three above */
ba23dbf1
LP
261 JSON_DEBUG = 1 << 4, /* Indicates that this log message is a debug message */
262 JSON_WARNING = 1 << 5, /* Indicates that this log message is a warning message */
cd0b6c53
LP
263} JsonDispatchFlags;
264
265typedef int (*JsonDispatchCallback)(const char *name, JsonVariant *variant, JsonDispatchFlags flags, void *userdata);
266
267typedef struct JsonDispatch {
268 const char *name;
269 JsonVariantType type;
270 JsonDispatchCallback callback;
271 size_t offset;
272 JsonDispatchFlags flags;
273} JsonDispatch;
274
275int json_dispatch(JsonVariant *v, const JsonDispatch table[], JsonDispatchCallback bad, JsonDispatchFlags flags, void *userdata);
276
277int json_dispatch_string(const char *name, JsonVariant *variant, JsonDispatchFlags flags, void *userdata);
19a209cc 278int json_dispatch_const_string(const char *name, JsonVariant *variant, JsonDispatchFlags flags, void *userdata);
cd0b6c53
LP
279int json_dispatch_strv(const char *name, JsonVariant *variant, JsonDispatchFlags flags, void *userdata);
280int json_dispatch_boolean(const char *name, JsonVariant *variant, JsonDispatchFlags flags, void *userdata);
281int json_dispatch_tristate(const char *name, JsonVariant *variant, JsonDispatchFlags flags, void *userdata);
282int json_dispatch_variant(const char *name, JsonVariant *variant, JsonDispatchFlags flags, void *userdata);
283int json_dispatch_integer(const char *name, JsonVariant *variant, JsonDispatchFlags flags, void *userdata);
284int json_dispatch_unsigned(const char *name, JsonVariant *variant, JsonDispatchFlags flags, void *userdata);
285int json_dispatch_uint32(const char *name, JsonVariant *variant, JsonDispatchFlags flags, void *userdata);
286int json_dispatch_int32(const char *name, JsonVariant *variant, JsonDispatchFlags flags, void *userdata);
a42ef715
LP
287int json_dispatch_uid_gid(const char *name, JsonVariant *variant, JsonDispatchFlags flags, void *userdata);
288int json_dispatch_user_group_name(const char *name, JsonVariant *variant, JsonDispatchFlags flags, void *userdata);
289int json_dispatch_id128(const char *name, JsonVariant *variant, JsonDispatchFlags flags, void *userdata);
290int json_dispatch_unsupported(const char *name, JsonVariant *variant, JsonDispatchFlags flags, void *userdata);
cd0b6c53 291
ab1a1ba5 292assert_cc(sizeof(uintmax_t) == sizeof(uint64_t));
cd0b6c53
LP
293#define json_dispatch_uint64 json_dispatch_unsigned
294
ab1a1ba5 295assert_cc(sizeof(intmax_t) == sizeof(int64_t));
cd0b6c53
LP
296#define json_dispatch_int64 json_dispatch_integer
297
298static inline int json_dispatch_level(JsonDispatchFlags flags) {
299
300 /* Did the user request no logging? If so, then never log higher than LOG_DEBUG. Also, if this is marked as
301 * debug message, then also log at debug level. */
302
303 if (!(flags & JSON_LOG) ||
304 (flags & JSON_DEBUG))
305 return LOG_DEBUG;
306
307 /* Are we invoked in permissive mode, or is this explicitly marked as warning message? Then this should be
308 * printed at LOG_WARNING */
309 if (flags & (JSON_PERMISSIVE|JSON_WARNING))
310 return LOG_WARNING;
311
312 /* Otherwise it's an error. */
313 return LOG_ERR;
314}
315
316int json_log_internal(JsonVariant *variant, int level, int error, const char *file, int line, const char *func, const char *format, ...) _printf_(7, 8);
317
19130626 318#define json_log(variant, flags, error, ...) \
cd0b6c53 319 ({ \
19130626 320 int _level = json_dispatch_level(flags), _e = (error); \
cd0b6c53 321 (log_get_max_level() >= LOG_PRI(_level)) \
62c6bbbc 322 ? json_log_internal(variant, _level, _e, PROJECT_FILE, __LINE__, __func__, __VA_ARGS__) \
19130626 323 : -ERRNO_VALUE(_e); \
cd0b6c53
LP
324 })
325
0ac0787e
LP
326#define json_log_oom(variant, flags) \
327 json_log(variant, flags, SYNTHETIC_ERRNO(ENOMEM), "Out of memory.")
328
d520d519
LP
329#define JSON_VARIANT_STRING_CONST(x) _JSON_VARIANT_STRING_CONST(UNIQ, (x))
330
90b365ce 331#define _JSON_VARIANT_STRING_CONST(xq, x) \
d520d519 332 ({ \
90b365ce 333 _align_(2) static const char UNIQ_T(json_string_const, xq)[] = (x); \
d520d519
LP
334 assert((((uintptr_t) UNIQ_T(json_string_const, xq)) & 1) == 0); \
335 (JsonVariant*) ((uintptr_t) UNIQ_T(json_string_const, xq) + 1); \
336 })
337
faca141c
LP
338int json_variant_unbase64(JsonVariant *v, void **ret, size_t *ret_size);
339
cd0b6c53
LP
340const char *json_variant_type_to_string(JsonVariantType t);
341JsonVariantType json_variant_type_from_string(const char *s);